Matplotlib: Annotate Subplots in a Figure with A, B, C [duplicate]

Question

When submitting papers to scientific journals one quite frequently needs to enumerate the different subplots of a figure with A, B, ... .

This sounds like a very common problem and I was trying to find an elegant way to do that automatically with matplotlib, but I was surprised to find nothing on it. But maybe I am not using the right search terms. Ideally, I am searching for a way to annotate such that the letters stay in place relative to the subplot if the figure is resized or the subplot is moved via fig.subplots_adjust, fig.tight_layout, or similar.

Any help or solution will appreciated.

Answer 1

If you want the annotation relative to the subplot then plotting it using ax.text seems the most convenient way to me.

Consider something like:

import numpy as np import matplotlib.pyplot as plt import string  fig, axs = plt.subplots(2,2,figsize=(8,8)) axs = axs.flat  for n, ax in enumerate(axs):      ax.imshow(np.random.randn(10,10), interpolation='none')         ax.text(-0.1, 1.1, string.ascii_uppercase[n], transform=ax.transAxes,              size=20, weight='bold')